I've actually been hit by a dog before, too. I was on my way to the office one morning, driving down 55 (an extremely busy 2 lane highway during rush hour). Well, they are widening the road and a construction crew was out there and one of the idiots finds a 30 foot space between me and the car in front of me, so he sprints across, as I'm cursing him for taking that chance. He must have had his dog with him, because before I knew it, a dog hits the side of my car. Unfortunately, he didn't make it. The poor thing went under my rear tire, he must have hit the bottom part of the door and straight down.
Other than that, a couple of rabbits, birds, squirrels and you can run over frogs just going out my driveway on a daily basis.